1. Field of the Invention
The present invention relates to a document image data storing and controlling system, and more particularly to a document image data storing and controlling system for use in a storage device whose storage amount is limited, such as a portable storage device, etc.
2. Description of the Related Art
With the increasing popularity of PCs having higher performances and of input devices such as a scanner, etc. in recent years, application software for managing document image data by using PCs have become popular. With these application software, document image data is input to a PC and stored in a file, searched and displayed depending on need, thereby effectively using the document image data. Additionally, the progress of a character recognition technique or a structure recognition technique of document image data enables the document image data which is put into an electronic form to be character-recognized, so that it has become possible to save labor in inputting a document and in reusing the document.
Furthermore, the portable information devices available anywhere, to which addresses, telephone numbers, schedules, etc. of individuals, are input, have been widely used. As one type of such devices, a device for allowing the document image data of an electronic still camera or the document image data input from a facsimile modem via a telephone line to be stored, maintained, and generated, has emerged. There is the demand for inputting, searching, and referencing the document image data with such a portable dedicated device in a similar manner as with a desktop PC.
An amount of data of one piece of document image data is 10 to 100 times text data, even if it is compressed with a dedicated compression method (such as the MMR, etc.). This is really a huge amount. Document image data is used by desktop PCs in most cases. Since desktop PCs can use a storage device having a large amount of storage amount such as a magnetic disk, an optical disk, etc., almost no problem is posed in terms of the amount of a storage amount. The storage amount of a portable information device is much less than that of a desktop PC. Therefore, the amount of document image data that can be stored is very small.
Accordingly, if the document image data is handled with a portable information device, the storage amount soon becomes insufficient. Because a storage amount to which data can be newly input must be secured in such a case, the document image data in the storage area must be deleted.
Provided below is the explanation about a conventional data storing system for use in a storage device whose amount is limited, by referring to FIGS. 1 and 2. FIG. 1 is a block diagram exemplifying the configuration of a first conventional data storing system. This conventional example is disclosed by the following document 1.
Document 1: Japanese Patent Application (TOKUGANHEI) No. 1-242094 (Japanese Laid-open Patent Publication (TOKKAIHEI) No. 3-105558) Document Editing Device Inventor: Isao YAMAZAKI
The first conventional system shown in FIG. 1 comprises a data input/output unit 1 for externally inputting/outputting data; a data storing unit 2 for storing data; a data amount managing unit 3 for managing an amount of stored data; a data deletion instructing unit 4 for instructing data deletion based on the output of the data amount managing unit 3; and a data deleting unit 5 for deleting the data stored in the data storing unit 2.
In FIG. 1, the amount of data stored in the data storing unit 2 is managed by the data amount managing unit 3. Assuming that a remaining storage amount is equal to or less than ten pages in terms of the number of pages of a document, for example, a user is made to specify the name of the document image data and a display process or a print process for that data. After the specified process is performed, all pieces of image data forming one document are deleted. The first conventional system secures a storage area in such a way.
FIG. 2 is a block diagram exemplifying the configuration of a second conventional system. This conventional system is disclosed by the following document 2.
Document 2: Japanese Patent Application (TOKUGANSHO) No. 63-219327 (Japanese Laid-open Patent Publication (TOKKAIHEI) No. 2-066654) Cache Memory Controlling System Inventor: Hiroaki HARA
In FIG. 2, the amount of data stored in the data storing unit 2 is managed by the data amount managing unit 3 in a similar manner as in FIG. 1. If the storage amount becomes insufficient, for example, data to which fewer accesses are made is automatically deleted by a data deleting unit 6, thereby securing a storage area for new data.
As described above, a document image which was previously input must be deleted in a unit of an entire document each time document image data is newly input, so as to secure a new storage area when a storage amount draws near to its limitation. Accordingly, the conventional systems have a problem in that it is difficult to keep each document image data for a long period of time.
The object of the present invention is to provide a document image data storing and controlling system for automatically securing a storage area for new document image data while leaving effective information in each document image data for a long period, without merely deleting document image data.
An embodiment of the present invention provides a document image data storing and controlling system which comprises a document image data storing unit for storing document image data which is divided into partial image data; and a document image data rewriting unit for rewriting the document image data so as to reduce the amount of the partial image data forming the stored document image data. Generally, document image data includes the areas having the attributes such as a graphic, a table, a title, a text, etc. as the image data of a single page. According to the present invention, the division of the document image data into partial image data in the areas according to these attributes is called xe2x80x9cstructurizationxe2x80x9d. With the document image data storing and controlling system according to the present invention, the partial image data having an attribute whose degree of importance as information is low is deleted, or the resolution of that partial image data is lowered in the document image data, thereby reducing the total amount of the document image data. Consequently, the storage area for new document image data can be secured while leaving effective information in previously stored document image data.
Another embodiment of the present invention provides a computer-readable storage medium for storing a program which is to be executed by a computer, and includes the steps of storing document image data structurized into partial image data, and rewriting the document image data in order to reduce the amount of the partial image data forming the stored document image data in order to control the storage of the document image data.
The document image data storing and controlling system which achieves the above described object of the present invention can be implemented also by making a computer read a program stored onto a storage medium, and execute the program.
A further embodiment of the present invention provides a document image data storing and controlling method comprising the steps of storing document image data structurized into partial image data, and rewriting the document image data in order to reduce the amount of the partial image data forming the document image data when the amount of the stored document image data reaches a predetermined amount. This method allows a storage area for new document image data to be automatically secured while leaving effective information in respective document image data.